Inflation Reduction Act 2024 Medicare Part D Plans. Insurers will limit monthly premium increases to $35 from the prior year. In 2025, 32% of medicare advantage plans will offer some reduction in the part b premium, higher than the share in 2024 (19%) (figure 1).

This is a 16% decrease from the 2024 average premium of. Nationally, the average bid from part d plan sponsors increased from $64.28 a month in 2024 to $179.45 in 2025.